Andrew's git / gitweb.git / builtin/describe.c
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builtin / describe.con commit rebase: use 'git stash store' to simplify logic (20351bb)
   1#include "cache.h"
   2#include "commit.h"
   3#include "tag.h"
   4#include "refs.h"
   5#include "builtin.h"
   6#include "exec_cmd.h"
   7#include "parse-options.h"
   8#include "diff.h"
   9#include "hash.h"
  10
  11#define SEEN            (1u<<0)
  12#define MAX_TAGS        (FLAG_BITS - 1)
  13
  14static const char * const describe_usage[] = {
  15        N_("git describe [options] <committish>*"),
  16        N_("git describe [options] --dirty"),
  17        NULL
  18};
  19
  20static int debug;       /* Display lots of verbose info */
  21static int all; /* Any valid ref can be used */
  22static int tags;        /* Allow lightweight tags */
  23static int longformat;
  24static int abbrev = -1; /* unspecified */
  25static int max_candidates = 10;
  26static struct hash_table names;
  27static int have_util;
  28static const char *pattern;
  29static int always;
  30static const char *dirty;
  31
  32/* diff-index command arguments to check if working tree is dirty. */
  33static const char *diff_index_args[] = {
  34        "diff-index", "--quiet", "HEAD", "--", NULL
  35};
  36
  37
  38struct commit_name {
  39        struct commit_name *next;
  40        unsigned char peeled[20];
  41        struct tag *tag;
  42        unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */
  43        unsigned name_checked:1;
  44        unsigned char sha1[20];
  45        const char *path;
  46};
  47static const char *prio_names[] = {
  48        "head", "lightweight", "annotated",
  49};
  50
  51static inline unsigned int hash_sha1(const unsigned char *sha1)
  52{
  53        unsigned int hash;
  54        memcpy(&hash, sha1, sizeof(hash));
  55        return hash;
  56}
  57
  58static inline struct commit_name *find_commit_name(const unsigned char *peeled)
  59{
  60        struct commit_name *n = lookup_hash(hash_sha1(peeled), &names);
  61        while (n && !!hashcmp(peeled, n->peeled))
  62                n = n->next;
  63        return n;
  64}
  65
  66static int set_util(void *chain, void *data)
  67{
  68        struct commit_name *n;
  69        for (n = chain; n; n = n->next) {
  70                struct commit *c = lookup_commit_reference_gently(n->peeled, 1);
  71                if (c)
  72                        c->util = n;
  73        }
  74        return 0;
  75}
  76
  77static int replace_name(struct commit_name *e,
  78                               int prio,
  79                               const unsigned char *sha1,
  80                               struct tag **tag)
  81{
  82        if (!e || e->prio < prio)
  83                return 1;
  84
  85        if (e->prio == 2 && prio == 2) {
  86                /* Multiple annotated tags point to the same commit.
  87                 * Select one to keep based upon their tagger date.
  88                 */
  89                struct tag *t;
  90
  91                if (!e->tag) {
  92                        t = lookup_tag(e->sha1);
  93                        if (!t || parse_tag(t))
  94                                return 1;
  95                        e->tag = t;
  96                }
  97
  98                t = lookup_tag(sha1);
  99                if (!t || parse_tag(t))
 100                        return 0;
 101                *tag = t;
 102
 103                if (e->tag->date < t->date)
 104                        return 1;
 105        }
 106
 107        return 0;
 108}
 109
 110static void add_to_known_names(const char *path,
 111                               const unsigned char *peeled,
 112                               int prio,
 113                               const unsigned char *sha1)
 114{
 115        struct commit_name *e = find_commit_name(peeled);
 116        struct tag *tag = NULL;
 117        if (replace_name(e, prio, sha1, &tag)) {
 118                if (!e) {
 119                        void **pos;
 120                        e = xmalloc(sizeof(struct commit_name));
 121                        hashcpy(e->peeled, peeled);
 122                        pos = insert_hash(hash_sha1(peeled), e, &names);
 123                        if (pos) {
 124                                e->next = *pos;
 125                                *pos = e;
 126                        } else {
 127                                e->next = NULL;
 128                        }
 129                }
 130                e->tag = tag;
 131                e->prio = prio;
 132                e->name_checked = 0;
 133                hashcpy(e->sha1, sha1);
 134                e->path = path;
 135        }
 136}
 137
 138static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 139{
 140        int is_tag = !prefixcmp(path, "refs/tags/");
 141        unsigned char peeled[20];
 142        int is_annotated, prio;
 143
 144        /* Reject anything outside refs/tags/ unless --all */
 145        if (!all && !is_tag)
 146                return 0;
 147
 148        /* Accept only tags that match the pattern, if given */
 149        if (pattern && (!is_tag || fnmatch(pattern, path + 10, 0)))
 150                return 0;
 151
 152        /* Is it annotated? */
 153        if (!peel_ref(path, peeled)) {
 154                is_annotated = !!hashcmp(sha1, peeled);
 155        } else {
 156                hashcpy(peeled, sha1);
 157                is_annotated = 0;
 158        }
 159
 160        /*
 161         * By default, we only use annotated tags, but with --tags
 162         * we fall back to lightweight ones (even without --tags,
 163         * we still remember lightweight ones, only to give hints
 164         * in an error message).  --all allows any refs to be used.
 165         */
 166        if (is_annotated)
 167                prio = 2;
 168        else if (is_tag)
 169                prio = 1;
 170        else
 171                prio = 0;
 172
 173        add_to_known_names(all ? path + 5 : path + 10, peeled, prio, sha1);
 174        return 0;
 175}
 176
 177struct possible_tag {
 178        struct commit_name *name;
 179        int depth;
 180        int found_order;
 181        unsigned flag_within;
 182};
 183
 184static int compare_pt(const void *a_, const void *b_)
 185{
 186        struct possible_tag *a = (struct possible_tag *)a_;
 187        struct possible_tag *b = (struct possible_tag *)b_;
 188        if (a->depth != b->depth)
 189                return a->depth - b->depth;
 190        if (a->found_order != b->found_order)
 191                return a->found_order - b->found_order;
 192        return 0;
 193}
 194
 195static unsigned long finish_depth_computation(
 196        struct commit_list **list,
 197        struct possible_tag *best)
 198{
 199        unsigned long seen_commits = 0;
 200        while (*list) {
 201                struct commit *c = pop_commit(list);
 202                struct commit_list *parents = c->parents;
 203                seen_commits++;
 204                if (c->object.flags & best->flag_within) {
 205                        struct commit_list *a = *list;
 206                        while (a) {
 207                                struct commit *i = a->item;
 208                                if (!(i->object.flags & best->flag_within))
 209                                        break;
 210                                a = a->next;
 211                        }
 212                        if (!a)
 213                                break;
 214                } else
 215                        best->depth++;
 216                while (parents) {
 217                        struct commit *p = parents->item;
 218                        parse_commit(p);
 219                        if (!(p->object.flags & SEEN))
 220                                commit_list_insert_by_date(p, list);
 221                        p->object.flags |= c->object.flags;
 222                        parents = parents->next;
 223                }
 224        }
 225        return seen_commits;
 226}
 227
 228static void display_name(struct commit_name *n)
 229{
 230        if (n->prio == 2 && !n->tag) {
 231                n->tag = lookup_tag(n->sha1);
 232                if (!n->tag || parse_tag(n->tag))
 233                        die(_("annotated tag %s not available"), n->path);
 234        }
 235        if (n->tag && !n->name_checked) {
 236                if (!n->tag->tag)
 237                        die(_("annotated tag %s has no embedded name"), n->path);
 238                if (strcmp(n->tag->tag, all ? n->path + 5 : n->path))
 239                        warning(_("tag '%s' is really '%s' here"), n->tag->tag, n->path);
 240                n->name_checked = 1;
 241        }
 242
 243        if (n->tag)
 244                printf("%s", n->tag->tag);
 245        else
 246                printf("%s", n->path);
 247}
 248
 249static void show_suffix(int depth, const unsigned char *sha1)
 250{
 251        printf("-%d-g%s", depth, find_unique_abbrev(sha1, abbrev));
 252}
 253
 254static void describe(const char *arg, int last_one)
 255{
 256        unsigned char sha1[20];
 257        struct commit *cmit, *gave_up_on = NULL;
 258        struct commit_list *list;
 259        struct commit_name *n;
 260        struct possible_tag all_matches[MAX_TAGS];
 261        unsigned int match_cnt = 0, annotated_cnt = 0, cur_match;
 262        unsigned long seen_commits = 0;
 263        unsigned int unannotated_cnt = 0;
 264
 265        if (get_sha1(arg, sha1))
 266                die(_("Not a valid object name %s"), arg);
 267        cmit = lookup_commit_reference(sha1);
 268        if (!cmit)
 269                die(_("%s is not a valid '%s' object"), arg, commit_type);
 270
 271        n = find_commit_name(cmit->object.sha1);
 272        if (n && (tags || all || n->prio == 2)) {
 273                /*
 274                 * Exact match to an existing ref.
 275                 */
 276                display_name(n);
 277                if (longformat)
 278                        show_suffix(0, n->tag ? n->tag->tagged->sha1 : sha1);
 279                if (dirty)
 280                        printf("%s", dirty);
 281                printf("\n");
 282                return;
 283        }
 284
 285        if (!max_candidates)
 286                die(_("no tag exactly matches '%s'"), sha1_to_hex(cmit->object.sha1));
 287        if (debug)
 288                fprintf(stderr, _("searching to describe %s\n"), arg);
 289
 290        if (!have_util) {
 291                for_each_hash(&names, set_util, NULL);
 292                have_util = 1;
 293        }
 294
 295        list = NULL;
 296        cmit->object.flags = SEEN;
 297        commit_list_insert(cmit, &list);
 298        while (list) {
 299                struct commit *c = pop_commit(&list);
 300                struct commit_list *parents = c->parents;
 301                seen_commits++;
 302                n = c->util;
 303                if (n) {
 304                        if (!tags && !all && n->prio < 2) {
 305                                unannotated_cnt++;
 306                        } else if (match_cnt < max_candidates) {
 307                                struct possible_tag *t = &all_matches[match_cnt++];
 308                                t->name = n;
 309                                t->depth = seen_commits - 1;
 310                                t->flag_within = 1u << match_cnt;
 311                                t->found_order = match_cnt;
 312                                c->object.flags |= t->flag_within;
 313                                if (n->prio == 2)
 314                                        annotated_cnt++;
 315                        }
 316                        else {
 317                                gave_up_on = c;
 318                                break;
 319                        }
 320                }
 321                for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 322                        struct possible_tag *t = &all_matches[cur_match];
 323                        if (!(c->object.flags & t->flag_within))
 324                                t->depth++;
 325                }
 326                if (annotated_cnt && !list) {
 327                        if (debug)
 328                                fprintf(stderr, _("finished search at %s\n"),
 329                                        sha1_to_hex(c->object.sha1));
 330                        break;
 331                }
 332                while (parents) {
 333                        struct commit *p = parents->item;
 334                        parse_commit(p);
 335                        if (!(p->object.flags & SEEN))
 336                                commit_list_insert_by_date(p, &list);
 337                        p->object.flags |= c->object.flags;
 338                        parents = parents->next;
 339                }
 340        }
 341
 342        if (!match_cnt) {
 343                const unsigned char *sha1 = cmit->object.sha1;
 344                if (always) {
 345                        printf("%s", find_unique_abbrev(sha1, abbrev));
 346                        if (dirty)
 347                                printf("%s", dirty);
 348                        printf("\n");
 349                        return;
 350                }
 351                if (unannotated_cnt)
 352                        die(_("No annotated tags can describe '%s'.\n"
 353                            "However, there were unannotated tags: try --tags."),
 354                            sha1_to_hex(sha1));
 355                else
 356                        die(_("No tags can describe '%s'.\n"
 357                            "Try --always, or create some tags."),
 358                            sha1_to_hex(sha1));
 359        }
 360
 361        qsort(all_matches, match_cnt, sizeof(all_matches[0]), compare_pt);
 362
 363        if (gave_up_on) {
 364                commit_list_insert_by_date(gave_up_on, &list);
 365                seen_commits--;
 366        }
 367        seen_commits += finish_depth_computation(&list, &all_matches[0]);
 368        free_commit_list(list);
 369
 370        if (debug) {
 371                for (cur_match = 0; cur_match < match_cnt; cur_match++) {
 372                        struct possible_tag *t = &all_matches[cur_match];
 373                        fprintf(stderr, " %-11s %8d %s\n",
 374                                prio_names[t->name->prio],
 375                                t->depth, t->name->path);
 376                }
 377                fprintf(stderr, _("traversed %lu commits\n"), seen_commits);
 378                if (gave_up_on) {
 379                        fprintf(stderr,
 380                                _("more than %i tags found; listed %i most recent\n"
 381                                "gave up search at %s\n"),
 382                                max_candidates, max_candidates,
 383                                sha1_to_hex(gave_up_on->object.sha1));
 384                }
 385        }
 386
 387        display_name(all_matches[0].name);
 388        if (abbrev)
 389                show_suffix(all_matches[0].depth, cmit->object.sha1);
 390        if (dirty)
 391                printf("%s", dirty);
 392        printf("\n");
 393
 394        if (!last_one)
 395                clear_commit_marks(cmit, -1);
 396}
 397
 398int cmd_describe(int argc, const char **argv, const char *prefix)
 399{
 400        int contains = 0;
 401        struct option options[] = {
 402                OPT_BOOLEAN(0, "contains",   &contains, N_("find the tag that comes after the commit")),
 403                OPT_BOOLEAN(0, "debug",      &debug, N_("debug search strategy on stderr")),
 404                OPT_BOOLEAN(0, "all",        &all, N_("use any ref")),
 405                OPT_BOOLEAN(0, "tags",       &tags, N_("use any tag, even unannotated")),
 406                OPT_BOOLEAN(0, "long",       &longformat, N_("always use long format")),
 407                OPT__ABBREV(&abbrev),
 408                OPT_SET_INT(0, "exact-match", &max_candidates,
 409                            N_("only output exact matches"), 0),
 410                OPT_INTEGER(0, "candidates", &max_candidates,
 411                            N_("consider <n> most recent tags (default: 10)")),
 412                OPT_STRING(0, "match",       &pattern, N_("pattern"),
 413                           N_("only consider tags matching <pattern>")),
 414                OPT_BOOLEAN(0, "always",     &always,
 415                           N_("show abbreviated commit object as fallback")),
 416                {OPTION_STRING, 0, "dirty",  &dirty, N_("mark"),
 417                           N_("append <mark> on dirty working tree (default: \"-dirty\")"),
 418                 PARSE_OPT_OPTARG, NULL, (intptr_t) "-dirty"},
 419                OPT_END(),
 420        };
 421
 422        git_config(git_default_config, NULL);
 423        argc = parse_options(argc, argv, prefix, options, describe_usage, 0);
 424        if (abbrev < 0)
 425                abbrev = DEFAULT_ABBREV;
 426
 427        if (max_candidates < 0)
 428                max_candidates = 0;
 429        else if (max_candidates > MAX_TAGS)
 430                max_candidates = MAX_TAGS;
 431
 432        save_commit_buffer = 0;
 433
 434        if (longformat && abbrev == 0)
 435                die(_("--long is incompatible with --abbrev=0"));
 436
 437        if (contains) {
 438                const char **args = xmalloc((7 + argc) * sizeof(char *));
 439                int i = 0;
 440                args[i++] = "name-rev";
 441                args[i++] = "--name-only";
 442                args[i++] = "--no-undefined";
 443                if (always)
 444                        args[i++] = "--always";
 445                if (!all) {
 446                        args[i++] = "--tags";
 447                        if (pattern) {
 448                                char *s = xmalloc(strlen("--refs=refs/tags/") + strlen(pattern) + 1);
 449                                sprintf(s, "--refs=refs/tags/%s", pattern);
 450                                args[i++] = s;
 451                        }
 452                }
 453                memcpy(args + i, argv, argc * sizeof(char *));
 454                args[i + argc] = NULL;
 455                return cmd_name_rev(i + argc, args, prefix);
 456        }
 457
 458        init_hash(&names);
 459        for_each_rawref(get_name, NULL);
 460        if (!names.nr && !always)
 461                die(_("No names found, cannot describe anything."));
 462
 463        if (argc == 0) {
 464                if (dirty) {
 465                        static struct lock_file index_lock;
 466                        int fd;
 467
 468                        read_cache_preload(NULL);
 469                        refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED,
 470                                      NULL, NULL, NULL);
 471                        fd = hold_locked_index(&index_lock, 0);
 472                        if (0 <= fd)
 473                                update_index_if_able(&the_index, &index_lock);
 474
 475                        if (!cmd_diff_index(ARRAY_SIZE(diff_index_args) - 1,
 476                                            diff_index_args, prefix))
 477                                dirty = NULL;
 478                }
 479                describe("HEAD", 1);
 480        } else if (dirty) {
 481                die(_("--dirty is incompatible with committishes"));
 482        } else {
 483                while (argc-- > 0) {
 484                        describe(*argv++, argc == 0);
 485                }
 486        }
 487        return 0;
 488}